Transcytosis - An effective targeting strategy that is complementary to "EPR effect" for pancreatic cancer nano drug delivery

Emerging Roles of Nanozyme in Tumor Metabolism Regulation: Mechanisms, Applications, and Future Directions

Nanozymes, nanomaterials with intrinsic enzyme activity, have garnered significant attention in recent years due to their catalytic abilities comparable to natural enzymes, cost-effectiveness, high catalytic activities, and stability against environmental fluctuations. As functional analogs of natural enzymes, nanozymes participate in various critical metabolic processes, including glucose metabolism, lactate metabolism, and the maintenance of redox homeostasis, all of which are essential for normal cellular functions. However, disruptions in these metabolic pathways frequently promote tumorigenesis and progression, making them potential therapeutic targets. While several therapies targeting tumor metabolism are currently in clinical or preclinical stages, their efficacy requires further enhancement. Consequently, nanozymes that target tumor metabolism are regarded as a promising therapeutic strategy. Despite extensive studies investigating the application of nanozymes in tumor metabolism, relevant reviews are relatively scarce. This article first introduces the physicochemical properties and biological behaviors of nanozymes. Subsequently, we analyze the role of nanozymes in tumor metabolism and explore their potential applications in tumor therapy. In conclusion, this review aims to foster innovative research in related fields and advance the development of nanozyme-based strategies for cancer diagnostics and therapeutics.

Beyond the EPR effect: Intravital microscopy analysis of nanoparticle drug delivery to tumors

Delivery of nanoparticles (NPs) to solid tumors has long relied on enhanced permeability and retention (EPR) effect, involving permeation of NPs through a leaky vasculature with prolonged retention by reduced lymphatic drainage in tumor. Recent research studies and clinical data challenge EPR concept, revealing alternative pathways and approaches of NP delivery. The area was significantly impacted by the implementation of intravital optical microscopy, unraveling delivery mechanisms at cellular level in vivo. This review presents analysis of the reasons for EPR heterogeneity in tumors and describes non-EPR based concepts for drug delivery, which can supplement the current paradigm. One of the approaches is targeting tumor endothelium by NPs with subsequent intravascular drug release and gradient-driven drug transport to tumor interstitium. Others exploit various immune cells for tumor infiltration and breaking endothelial barriers. Finally, we discuss the involvement of active transcytosis through endothelial cells in NP delivery. This review aims to inspire further understanding of the process of NP extravasation in tumors and provide insights for developing next-generation nanomedicines with improved delivery.

Acoustically Driven Hybrid Nanocrystals for In Vivo Pancreatic Cancer Treatment

New treatment strategies are urgently needed for pancreatic ductal adenocarcinoma (PDAC), which is one of the deadliest tumors nowadays. PDAC is marked by hypoxia, intrinsic chemoresistance, a "cold" tumor microenvironment, and dense desmoplastic stroma, which hinders drug penetration. This study investigates the combined effect of iron-doped, lipid-coated zinc oxide nanoparticles enhanced with a fluorescent sonosensitizer and local ultrasound stimulation in treating PDAC. Nanoparticles were synthesized and coated by lipids, and their physiochemical properties were characterized by assessing reproducibility, stability, and efficient inclusion of the sonosensitizer. In vitro, sonosensitizer-enhanced nanoconstructs were tested on a KPC murine PDAC cell line in combination with ultrasound to evaluate their cytotoxicity and assess their efficacy. In vivo, NPs were further coupled with AlexaFluor 700 to allow their localization over time, and the nanoconstructs were intratumorally administered to a subcutaneous murine PDAC model to enhance local bioavailability and tumor visualization and minimize off-target effects of systemic delivery. Biodistribution, efficacy, flow cytometry, and survival studies were carried out on different cohorts of mice. The sonosensitizer-enhanced nanoconstructs, combined with ultrasound, triggered significant reactive oxygen species (ROS) production, reducing the KPC cell viability. In vivo, the antitumor efficacy was particularly pronounced with ultrasound stimulation, demonstrating a synergistic interaction between the nanoparticles and ultrasound. Moreover, increased immune cell infiltration, enhanced cancer cell apoptosis, and prolonged survival of the treated animals were achieved. These findings highlight the potential of a synergistic therapeutic approach combining lipid-coated sonosensitizer-loaded nanoparticles and ultrasound stimulation as an effective therapy for PDAC and in situ monitoring.

Transcytosis: an effective mechanism to enhance nanoparticle extravasation and infiltration through biological barriers

Nanoparticles (NPs)1have been explored as drugs carriers for treating tumors and central nervous system (CNS)2diseases and for oral administration. However, they lack satisfactory clinical efficacy due to poor extravasation and infiltration through biological barriers to target tissues. Most clinical antitumor NPs have been designed based on enhanced permeability and retention effects which are insufficient and heterogeneous in human tumors. The tight junctions33TJs: tight junctionsof the blood-brain barrier44BBB: blood-brain barrierand the small intestinal epithelium severely impede NPs from being transported into the CNS and blood circulation, respectively. By contrast, transcytosis enables NPs to bypass these physiological barriers and enhances their infiltration into target tissues by active transport. Here, we systematically review the mechanisms and putative application of NP transcytosis for targeting tumor and CNS tissues, explore oral NP administration, and propose future research directions in the field of NP transcytosis.

Surface Functionalization of Nanocarriers with Anti-EGFR Ligands for Cancer Active Targeting

Active cancer targeting consists of the selective recognition of overexpressed biomarkers on cancer cell surfaces or within the tumor microenvironment, enabled by ligands conjugated to drug carriers. Nanoparticle (NP)-based systems are highly relevant for such an approach due to their large surface area which is amenable to a variety of chemical modifications. Over the past decades, several studies have debated the efficiency of passive targeting, highlighting active targeting as a more specific and selective approach. The choice of conjugation chemistry for attaching ligands to nanocarriers is critical to ensure a stable and robust system. Among the panel of cancer biomarkers, the epidermal growth factor receptor (EGFR) stands as one of the most frequently overexpressed receptors in different cancer types. The design and development of nanocarriers with surface-bound anti-EGFR ligands are vital for targeted therapy, relying on their facilitated capture by EGFR-overexpressing tumor cells and enabling receptor-mediated endocytosis to improve drug accumulation within the tumor microenvironment. In this review, we examine several examples of the most recent and significant anti-EGFR nanocarriers and explore the various conjugation strategies for NP functionalization with anti-EGFR biomolecules and small molecular ligands. In addition, we also describe some of the most common characterization techniques to confirm and analyze the conjugation patterns.

Enhanced safety and efficacy profile of CD40 antibody upon encapsulation in pHe-triggered membrane-adhesive nanoliposomes

AIM

To develop pH (pHe)-triggered membrane adhesive nanoliposome (pHTANL) of CD40a to enhance anti-tumor activity in pancreatic cancer while reducing systemic toxicity.

MATERIALS AND METHODS

A small library of nanoliposomes (NL) with various lipid compositions were synthesized to prepare pH (pHe)-triggered membrane adhesive nanoliposome (pHTANL). Physical and functional characterization of pHTANL-CD40a was performed via dynamic light scattering (DLS), Transmission Electron Microscopy (TEM), confocal microscopy, and flow cytometry. In vivo studies were performed using PDAC (Panc02) transplanted mice. Tumor tissue was analyzed by flow cytometry, and plasma cytokines and liver enzymes were analyzed by ELISA.

RESULTS

pHTANL-CD40a reduced tumor growth, enhanced tumor immune infiltration/activation, and enhanced survival compared to vehicle and free-CD40a. Importantly, pHTANL-CD40a treatment resulted in significantly lower systemic toxicity as indicated by unchanged body weight, minimal organ deformity, and reduced serum levels of liver enzyme alanine transaminase (ALT) and inflammatory cytokine IL-6.

CONCLUSION

pHTANL-CD40a is more effective than free CD40a in anti-tumor activity, especially in altering the TME immune landscape for a potential therapeutic benefit in combination with immunotherapy.

Nanotechnology for the Diagnosis and Treatment of Liver Cancer

Liver cancer has become a major global health challenge due to its high incidence, high rate of late diagnosis and limited treatment options. Although there are many clinical treatments available for liver cancer, the cure rate is still very low, and now researchers have begun to explore new aspects of liver cancer treatment, and nanotechnology has shown great potential for improving diagnostic accuracy and therapeutic efficacy and is therefore a promising treatment option. In diagnosis, nanomaterials such as gold nanoparticles, magnetic nanoparticles, and silver nanoparticles can realize highly sensitive and specific detection of liver cancer biomarkers, supporting diagnosis and real-time monitoring of the disease process. In terms of treatment, nanocarriers can realize precise targeted delivery of drugs, improve the bioavailability of liver cancer therapeutic drugs and reduce systemic toxic side effects. In addition, advanced technologies such as nanoparticle-based photothermal therapy and photodynamic therapy provide innovative solutions to overcome drug resistance and local tumor ablation. Therefore, in this paper, we will introduce nanotechnology for hepatocellular carcinoma in terms of tumor marker detection, targeted drug delivery, and synergistic PDT/CDT therapy.

Enhancing tumor endothelial permeability using MUC18-targeted gold nanorods and mild hyperthermia

The Enhanced Permeability and Retention (EPR) effect, an elevated accumulation of drugs and nanoparticles in tumors versus in normal tissues, is a widely used concept in the field of cancer therapy. It assumes that the vasculature of solid tumors would possess abnormal, leaky endothelial cell barriers, allowing easy access of intravenous-delivered drugs and nanoparticles to tumor regions. However, the EPR effect is not always effective owing to the heterogeneity of tumor endothelium over time, location, and species. Herein, we introduce a unique nanoparticle-based approach, using MUC18-targeted gold nanorods coupled with mild hyperthermia, to specifically enhance tumor endothelial permeability. This improves the efficacy of traditional cancer therapy including photothermal therapy and anticancer drug delivery by increasing the transport of photo-absorbers and drugs across the tumor endothelium. Using single cell imaging tools and classic analytical approaches in molecular biology, we demonstrate that MUC18-targeted gold nanorods and mild hyperthermia enlarge the intercellular gaps of tumor endothelium by inducing circumferential actin remodeling, stress fiber formation, and cell contraction of adjacent endothelial cells. Considering MUC18 is overexpressed on a variety of tumor endothelium and cancer cells, this approach paves a new avenue to improve the efficacy of cancer therapy by actively enhancing the tumor endothelial permeability.

Pathophysiology-Driven Approaches for Overcoming Nanomedicine Resistance in Pancreatic Cancer

Tumor heterogeneity poses a significant challenge in cancer therapy. To address this, we analyze pharmacotherapeutic challenges by categorizing them into static and dynamic barriers, reframing these challenges to improve drug delivery, efficacy, and the development of controlled-release nanomedicines (CRNMs). This pathophysiology-driven approach facilitates the design of novel therapeutics tailored to overcome obstacles in pancreatic ductal adenocarcinoma (PDAC) using nanotechnology. Advanced biomaterials in nanodrug delivery systems offer innovative solutions by combining controlled release, stimuli sensitivity, and smart design strategies. CRNMs are engineered to modulate spatiotemporal signaling and control drug release in PDAC, where resistance to conventional therapies is particularly high. This review explores pharmacokinetic considerations for nanomedicine design, RNA interference (RNAi) for stromal modulation, and the development of targeted nanomedicine strategies. Additionally, we highlight the limitations of current animal models in capturing the complexities of PDAC and discuss notable clinical failures, such as PEGylated hyaluronidase (Phase III HALO 109-301 trial) and evofosfamide (TH-302) with gemcitabine (MAESTRO trial), underscoring the need for improved models and treatment strategies. By targeting pathways like Notch and Hedgehog and incorporating stimuli-sensitive and pathway-modulating agents, CRNMs offer a promising avenue to enhance drug penetration and efficacy, reshaping the paradigm of pancreatic cancer treatment.

Aspects and prospects of preclinical theranostic radiopharmaceutical development

This article provides an overview of preclinical theranostic radiopharmaceutical development, highlighting aspects of the preclinical development stages that can lead towards a clinical trial. The key stages of theranostic radiopharmaceutical development are outlined, including target selection, tracer development, radiopharmaceutical synthesis, automation and quality control, in vitro radiopharmaceutical analysis, selecting a suitable in vivo model, preclinical imaging and pharmacokinetic analysis, preclinical therapeutic analysis, dosimetry, toxicity, and preparing for clinical translation. Each stage is described and augmented with examples from the literature. Finally, an outlook on the prospects for the radiopharmaceutical theranostics field is provided.

The influence of various polymer coatings on the in vitro and in vivo properties of PLGA nanoparticles: Comprehensive study

Nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) with various surface chemistry are widely used in biomedicine for theranostic applications. The nature of the external coating of nanoparticles has a significant influence on their efficiency as drug carriers or visualization agents. However, information about the mechanisms of nanoparticle accumulation in tumors and the influence of their surface properties on biodistribution is scarce due to the lack of systematic evaluation. Here we investigate the effect of different polymer coatings of the surface on in vitro and in vivo properties of PLGA nanoparticles. Namely, cell binding efficiency, cytotoxicity, efficiency of fluorescent bioimaging, and tumor accumulation were tested. The highest binding efficiency in vitro and cytotoxicity were observed for positively charged polymers. Interestingly, in vivo fluorescent visualization of tumor-bearing mice and quantitative measurements of biodistribution of magnetite-loaded nanoparticles indicated different dependences of accumulation in tumors on the coating of PLGA nanoparticles. This means that nanoparticle surface properties can simultaneously enhance imaging efficiency and decrease quantitative accumulation in tumors. The obtained data demonstrate the complexity of the dependence of nanoparticles' effectiveness for theranostic applications on surface features. We believe that this study will contribute to the rational design of nanoparticles for effective cancer diagnostics and therapy.

Oral Formulation of 5-Aminosalicylic Acid-Hemoglobin Bio-Adhesive Nanoparticles Enhance Therapeutic Efficiency in Ulcerative Colitis Mice: A Preclinical Evaluation

The oral formulation design for colon-specific drug delivery brings some therapeutic benefits in the ulcerative colitis treatment. We recently reported the specific delivery of hemoglobin nanoparticles-conjugating 5-aminosalicylic acid (5-ASA-HbNPs) to the inflamed site. In the current study, the therapeutic effect of the 5-ASA-HbNPs formulation was confirmed in vivo. This evaluation of 5-ASA-HbNPs not only shows longer colonic retention time due to adhesive properties, also provides full support for it as compared with free 5-ASA. It was considered as a suitable bio-adhesive nanoparticle with mucoadhesive property to pass through the mucus layer and accumulate into the mucosa. In UC model mice, a two-fold decrease in the disease activity indexes and colon weight/length ratios was significantly observed in the group treated with 5-ASA-HbNPs. This group received one percent of the standard dosage of 5-ASA (50 μg/kg), while, a similar result was observed for a significant amount of free 5-ASA (5 mg/kg). Furthermore, microscopic images of histological sections of the extracted colons demonstrated that the 5-ASA-HbNPs and 5-ASA groups displayed instances of inflammatory damage within the colon. However, in comparison to the colitis group, the extent of this damage was relatively moderate, suggesting 5-ASA-HbNPs improved therapeutic efficacy with the lower dosage form.

Lipid-based nanosystems: the next generation of cancer immune therapy

Immunotherapy has become an important part of the oncotherapy arsenal. Its applicability in various cancer types is impressive, as well as its use of endogenous mechanisms to achieve desired ends. However, off-target or on-target-off-tumor toxicity, limited activity, lack of control in combination treatments and, especially for solid tumors, low local accumulation, have collectively limited clinical use thereof. These limitations are partially alleviated by delivery systems. Lipid-based nanoparticles (NPs) have emerged as revolutionary carriers due to favorable physicochemical characteristics, with specific applications and strengths particularly useful in immunotherapeutic agent delivery. The aim of this review is to highlight the challenges faced by immunotherapy and how lipid-based NPs have been, and may be further utilized to address such challenges. We discuss recent fundamental and clinical applications of NPs in a range of areas and provide a detailed discussion of the main obstacles in immune checkpoint inhibition therapies, adoptive cellular therapies, and cytokine therapies. We highlight how lipid-based nanosystems could address these through either delivery, direct modulation of the immune system, or targeting of the immunosuppressive tumor microenvironment. We explore advanced and emerging liposomal and lipid nanoparticle (LNP) systems for nucleic acid delivery, intrinsic and extrinsic stimulus-responsive formulations, and biomimetic lipid-based nanosystems in immunotherapy. Finally, we discuss the key challenges relating to the clinical use of lipid-based NP immunotherapies, suggesting future research directions for the near term to realize the potential of these innovative lipid-based nanosystems, as they become the crucial steppingstone towards the necessary enhancement of the efficacy of immunotherapy.

All-in-one nanotheranostic platform based on tumor microenvironment: new strategies in multimodal imaging and therapeutic protocol

Conventional tumor diagnosis and treatment approaches have significant limitations in clinical application, whereas personalized theranostistic nanoplatforms can ensure advanced diagnosis, precise treatment, and even a good prognosis in cancer. Tumor microenvironment (TME)-targeted therapeutic strategies offer absolute advantages in all aspects compared to tumor cell-targeted therapeutic strategies. It is essential to create a TME-responsive all-in-one nanotheranostic platform to facilitate individualized tumor treatment. Based on the TME-responsive multifunctional nanotheranostic platform, we focus on the combined use of multimodal imaging and therapeutic protocols and summary and outlooks on the latest advanced nanomaterials and structures for creating the integrated nanotheranostic system based on material science, which provide insights and reflections on the development of innovative TME-targeting tools for cancer theranostics.

Metabolism and structure of PDA as the target for new therapies: possibilities and limitations for nanotechnology

INTRODUCTION

Certainly, pancreatic ductal adenocarcinoma poses one of the greatest challenges in current oncology. The dense extracellular matrix and low vessel density in PDA tumor impede the effective delivery of drugs, primarily due to the short pharmacokinetics of most drugs and potential electrostatic interactions with stroma components.

AREA COVERED

Owing to the distinctive metabolism of PDA and challenges in accessing nutrients, there is a growing interest in cell metabolism inhibitors as a potential means to inhibit cancer development. However, even if suitable combinations of inhibitors are identified, the question about their administration remains, as the same hindrances that impede effective treatment with conventional drugs will also hinder the delivery of inhibitors. Methods including nanotechnology to increase drugs in PDA penetrations are reviewed and discussed.

EXPERT OPINION

Pancreatic cancer is one of the most difficult tumors to treat due to the small number of blood vessels, high content of extracellular matrix, and specialized resistance mechanisms of tumor cells. One possible method of treating this tumor is the use of metabolic inhibitors in combinations that show synergy. Despite promising results in in vitro tests, their effect is uncertain due to the tumor's structure. In the case of pancreatic cancer, priming of the tumor tissue is required through the sequential administration of drugs that generate blood vessels, increase blood flow, and enhance vascular permeability and extracellular matrix. The use of drug carriers with a size of 10-30 nm may be crucial in the therapy of this cancer.

Targeting the Gut: A Systematic Review of Specific Drug Nanocarriers

The intestine is essential for the modulation of nutrient absorption and the removal of waste. Gut pathologies, such as cancer, inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS), and celiac disease, which extensively impact gut functions, are thus critical for human health. Targeted drug delivery is essential to tackle these diseases, improve therapy efficacy, and minimize side effects. Recent strategies have taken advantage of both active and passive nanocarriers, which are designed to protect the drug until it reaches the correct delivery site and to modulate drug release via the use of different physical-chemical strategies. In this systematic review, we present a literature overview of the different nanocarriers used for drug delivery in a set of chronic intestinal pathologies, highlighting the rationale behind the controlled release of intestinal therapies. The overall aim is to provide the reader with useful information on the current approaches for gut targeting in novel therapeutic strategies.

The spatiotemporal journey of nanomedicines in solid tumors on their therapeutic efficacy

The rapid development of nanomedicines is revolutionizing the landscape of cancer treatment, while effectively delivering them into solid tumors remains a formidable challenge. Currently, there is a huge disconnect on therapeutic response between regulatory approved nanomedicines and laboratory reported nanoparticles. The discrepancy is mainly resulted from the failure of using the classic overall pharmacokinetics behaviors of nanomedicines in tumors to predict the antitumor efficacy. Increasing evidence has revealed that the therapeutic efficacy predominantly relies on the intratumoral spatiotemporal distribution of nanomedicines. This review focuses on the spatiotemporal distribution of systemically administered chemotherapeutic nanomedicines in solid tumor. Firstly, the intratumoral biological barriers that regulate the spatiotemporal distribution of nanomedicines are described in detail. Next, the influences on antitumor efficacy caused by the spatial distribution and temporal drug release of nanomedicines are emphatically analyzed. Then, current methodologies for evaluating the spatiotemporal distribution of nanomedicines are summarized. Finally, the advanced strategies to positively modulate the spatiotemporal distribution of nanomedicines for an optimal tumor therapy are comprehensively reviewed.

Transcytosis-Inducing Multifunctional Albumin Nanomedicines with Deep Penetration Ability for Image-Guided Solid Tumor Treatment

Transcytosis is an active transcellular transportation pathway that has garnered interest for overcoming the limited deep penetration of nanomedicines in solid tumors. In this study, a charge-convertible nanomedicine that facilitates deep penetration into solid tumors via transcytosis is designed. It is an albumin-based calcium phosphate nanomedicine loaded with IR820 (mAlb-820@CaP) for high-resolution photoacoustic imaging and enhanced photothermal therapy. Biomineralization on the surface stabilizes the albumin-IR820 complex during circulation and provides calcium ions (Ca2+ ) for tissue penetration on degradation in an acidic environment. pH-triggered transcytosis of the nanomedicine enabled by caveolae-mediated endocytosis and calcium ion-induced exocytosis in 2D cellular, 3D spheroid, and in vivo tumor models is demonstrated. Notably, the extravasation and penetration ability of the nanomedicine is observed in vivo using a high-resolution photoacoustic system, and nanomedicine shows the most potent photothermal antitumor effect in vivo. Overall, the strategy provides a versatile theragnosis platform for both noninvasive photoacoustic imaging and high therapeutic efficiency resulting from deep penetration of nanomedicine.

Orange-derived extracellular vesicles nanodrugs for efficient treatment of ovarian cancer assisted by transcytosis effect

Extracellular vesicles (EVs) have recently received much attention about the application of drug carriers due to their desirable properties such as nano-size, biocompatibility, and high stability. Herein, we demonstrate orange-derived extracellular vesicles (OEV) nanodrugs (DN@OEV) by modifying cRGD-targeted doxorubicin (DOX) nanoparticles (DN) onto the surface of OEV, enabling significantly enhancing tumor accumulation and penetration, thereby efficiently inhibiting the growth of ovarian cancer. The obtained DN@OEV enabled to inducement of greater transcytosis capability in ovarian cancer cells, which presented the average above 10-fold transcytosis effect compared with individual DN. It was found that DN@OEV could trigger receptor-mediated endocytosis to promote early endosome/recycling endosomes pathway for exocytosis and simultaneously reduce degradation in the early endosomes-late endosomes-lysosome pathway, thereby inducing the enhanced transcytosis. In particular, the zombie mouse model bearing orthotopic ovarian cancer further validated DN@OEV presented high accumulation and penetration in tumor tissue by the transcytosis process. Our study indicated the strategy in enhancing transcytosis has significant implications for improving the therapeutic efficacy of the drug delivery system.

Colorectal cancer cell exosome and cytoplasmic membrane for homotypic delivery of therapeutic molecules

Colorectal cancer (CRC) is one of the most common causes of death in the world. The multi-drug resistance, especially in metastatic colorectal cancer, drives the development of new strategies that secure a positive outcome and reduce undesirable side effects. Nanotechnology has made an impact in addressing some pharmacokinetic and safety issues related to administration of free therapeutic agents. However, demands of managing complex biointerfacing require equally complex methods for introducing stimuli-responsive or targeting elements. In order to procure a more efficient solution to the overcoming of biological barriers, the physiological functions of cancer cell plasma and exosomal membranes provided the source of highly functionalized coatings. Biomimetic nanovehicles based on colorectal cancer (CRC) membranes imparted enhanced biological compatibility, immune escape and protection to diverse classes of therapeutic molecules. When loaded with therapeutic load or used as a coating for other therapeutic nanovehicles, they provide highly efficient and selective cell targeting and uptake. This review presents a detailed overview of the recent application of homotypic biomimetic nanovehicles in the management of CRC. We also address some of the current possibilities and challenges associated with the CRC membrane biomimetics.

Cartilage oligomeric matrix protein overexpression is an independent poor prognostic indicator in patients with intrahepatic cholangiocarcinoma

Cartilage oligomeric matrix protein (COMP) interacts with various extracellular matrix proteins in tissues. Elevated COMP levels recently linked to worse overall survival in multiple cancer types. COMP's significance in intrahepatic cholangiocarcinoma (iCCA) remains uncertain. Here we report a retrospective study to explore COMP's impact on iCCA outcomes. We collected 182 patients' iCCA tumor tissues. COMP overexpression was associated with adverse factors like R1 resection (p = 0.008), advanced T stage (p < 0.001), large duct type (p = 0.004), and poorly differentiated histology (p = 0.002). COMP overexpression correlates with poorer DFS (HR, 3.651; p = 0.001), OS (HR, 1.827; p = 0.023), LRFS (HR, 4.077; p < 0.001), and MFS (HR, 3.718; p < 0.001). High COMP expression ties to worse overall survival (p = 0.0001), DSS (p < 0.0001), LRFS (p < 0.0001), and MFS (p < 0.0001). In conclusion, COMP overexpression links to poor prognosis and pathological features in iCCA, indicating its potential as a biomarker.

Tumor Abnormality-Oriented Nanomedicine Design

Anticancer nanomedicines have been proven effective in mitigating the side effects of chemotherapeutic drugs. However, challenges remain in augmenting their therapeutic efficacy. Nanomedicines responsive to the pathological abnormalities in the tumor microenvironment (TME) are expected to overcome the biological limitations of conventional nanomedicines, enhance the therapeutic efficacies, and further reduce the side effects. This Review aims to quantitate the various pathological abnormalities in the TME, which may serve as unique endogenous stimuli for the design of stimuli-responsive nanomedicines, and to provide a broad and objective perspective on the current understanding of stimuli-responsive nanomedicines for cancer treatment. We dissect the typical transport process and barriers of cancer drug delivery, highlight the key design principles of stimuli-responsive nanomedicines designed to tackle the series of barriers in the typical drug delivery process, and discuss the "all-into-one" and "one-for-all" strategies for integrating the needed properties for nanomedicines. Ultimately, we provide insight into the challenges and future perspectives toward the clinical translation of stimuli-responsive nanomedicines.

Advances in Pancreatic Cancer Treatment by Nano-Based Drug Delivery Systems

Pancreatic cancer represents one of the most lethal cancer types worldwide, with a 5-year survival rate of less than 5%. Due to the inability to diagnose it promptly and the lack of efficacy of existing treatments, research and development of innovative therapies and new diagnostics are crucial to increase the survival rate and decrease mortality. Nanomedicine has been gaining importance as an innovative approach for drug delivery and diagnosis, opening new horizons through the implementation of smart nanocarrier systems, which can deliver drugs to the specific tissue or organ at an optimal concentration, enhancing treatment efficacy and reducing systemic toxicity. Varied materials such as lipids, polymers, and inorganic materials have been used to obtain nanoparticles and develop innovative drug delivery systems for pancreatic cancer treatment. In this review, it is discussed the main scientific advances in pancreatic cancer treatment by nano-based drug delivery systems. The advantages and disadvantages of such delivery systems in pancreatic cancer treatment are also addressed. More importantly, the different types of nanocarriers and therapeutic strategies developed so far are scrutinized.

Combination Therapy of Lox Inhibitor and Stimuli-Responsive Drug for Mechanochemically Synergistic Breast Cancer Treatment

Chemotherapy based on small molecule drugs, hormones, cycline kinase inhibitors, and monoclonal antibodies has been widely used for breast cancer treatment in the clinic but with limited efficacy, due to the poor specificity and tumor microenvironment (TME)-caused diffusion barrier. Although monotherapies targeting biochemical cues or physical cues in the TME have been developed, none of them can cope with the complex TME, while mechanochemical combination therapy remains largely to be explored. Herein, a combination therapy strategy based on an extracellular matrix (ECM) modulator and TME-responsive drug for the first attempt of mechanochemically synergistic treatment of breast cancer is developed. Specifically, based on overexpressed NAD(P)H quinone oxidoreductase 1 (NQO1) in breast cancer, a TME-responsive drug (NQO1-SN38) is designed and it is combined with the inhibitor (i.e., β-Aminopropionitrile, BAPN) for Lysyl oxidases (Lox) that contributes to the tumor stiffness, for mechanochemical therapy. It is demonstrated that NQO1 can trigger the degradation of NQO1-SN38 and release SN38, showing nearly twice tumor inhibition efficiency compared with SN38 treatment in vitro. Lox inhibition with BAPN significantly reduces collagen deposition and enhances drug penetration in tumor heterospheroids in vitro. It is further demonstrated that the mechanochemical therapy showed outstanding therapeutic efficacy in vivo, providing a promising approach for breast cancer therapy.

Biomembrane-wrapped gene delivery nanoparticles for cancer therapy

As a promising strategy, gene delivery for cancer treatment accepts encouraging progress due to its high efficacy, low toxicity, and exclusive selectivity. However, the delivery efficiency, specific biological distribution, targeted uptake, and biosafety of naked nucleic acid agents still face serious challenges, which limit further clinical application. To overcome the above bottleneck, safe and efficient functional nanovectors are developed to improve the delivery efficiency of nucleic acid agents. In recent years, emerging membrane-wrapped biomimetic nanoparticles (MBNPs) based on the concept of "imitating nature" are well known for their advantages, such as low immunogenicity and long cycle time, and especially play a crucial role in improving the overall efficiency of gene delivery and reducing adverse reactions. Therefore, combining MBNPs and gene delivery is an effective strategy to enhance tumor treatment efficiency. This review presents the mechanism of gene therapy and the current obstacles to gene delivery. Remarkably, the latest development of gene delivery MBNPs and the strategies to overcome these obstacles are summarized. Finally, the future challenges and prospects of gene delivery MBNPs toward clinical transformation are introduced. The principal purpose of this review is to discuss the biomedical potential of gene delivery MBNPs for cancer therapy and to provide guidance for further enhancing the efficiency of tumor gene therapy.

Lawsone encapsulated polylactic-co-glycolic acid nanoparticles modified with chitosan-folic acid successfully inhibited cell growth and triggered apoptosis in Panc-1 cancer cells

The present research aims to encapsulate lawsone in polylactic-co-glycolic acid (PLGA) nanoparticles modified with folic acid (FA) and chitosan (CS) to study its anticancer effects against Panc-1 cells. The nanoparticles were analysed in means of shape/size and zeta potential index using scanning electron microscope and dynamic light scattering. High-performance liquid chromatography was applied to evaluate the lawsone entrapment efficacy. The authors performed acridine orange/propidium iodide staining and flow cytometry to monitor apoptosis induction and cell cycle arrest. The expressions of apoptosis-related genes (BAX and BCL-2) were assessed by real time PCR. Nanoparticle antioxidative and antibacterial activities were examined by DPPH/ABTS scavenging assay, disk diffusion method, and minimum inhibitory concentration and minimum bactericidal concentration evaluation. The NPs were 229.65 nm, the encapsulation efficiency was 81%. The concentration of lawsone that exerts 50% cell growth inhibition (IC₅₀ ) against Panc-1 cells was calculated 118.4 μL. Apoptosis induction was evidenced by the increased number of orange cells and increased proportion of cells in G1-Sub phase respectively. Moreover, lawsone-loaded nanoparticle upregulated BAX gene expression, while downregulated BCL2expression, suggesting the activation of apoptotic pathway. The observed cytotoxic/apoptotic properties suggest that Lawson-loaded PLGA-FA-CS-NPs hold a great potential in pancreatic cancer treatment.

Delivery of Chemotherapy Agents and Nucleic Acids with pH-Dependent Nanoparticles

With less than one percent of systemically injected nanoparticles accumulating in tumors, several novel approaches have been spurred to direct and release the therapy in or near tumors. One such approach depends on the acidic pH of the extracellular matrix and endosomes of the tumor. With an average pH of 6.8, the extracellular tumor matrix provides a gradient for pH-responsive particles to accumulate, enabling greater specificity. Upon uptake by tumor cells, nanoparticles are further exposed to lower pHs, reaching a pH of 5 in late endosomes. Based on these two acidic environments in the tumor, various pH-dependent targeting strategies have been employed to release chemotherapy or the combination of chemotherapy and nucleic acids from macromolecules such as the keratin protein or polymeric nanoparticles. We will review these release strategies, including pH-sensitive linkages between the carrier and hydrophobic chemotherapy agent, the protonation and disruption of polymeric nanoparticles, an amalgam of these first two approaches, and the release of polymers shielding drug-loaded nanoparticles. While several pH-sensitive strategies have demonstrated marked antitumor efficacy in preclinical trials, many studies are early in their development with several obstacles that may limit their clinical use.

Drug Delivery Strategies for the Treatment of Pancreatic Cancer

Pancreatic cancer is fast becoming a global menace and it is projected to be the second leading cause of cancer-related death by 2030. Pancreatic adenocarcinomas, which develop in the pancreas' exocrine region, are the predominant type of pancreatic cancer, representing about 95% of total pancreatic tumors. The malignancy progresses asymptomatically, making early diagnosis difficult. It is characterized by excessive production of fibrotic stroma known as desmoplasia, which aids tumor growth and metastatic spread by remodeling the extracellular matrix and releasing tumor growth factors. For decades, immense efforts have been harnessed toward developing more effective drug delivery systems for pancreatic cancer treatment leveraging nanotechnology, immunotherapy, drug conjugates, and combinations of these approaches. However, despite the reported preclinical success of these approaches, no substantial progress has been made clinically and the prognosis for pancreatic cancer is worsening. This review provides insights into challenges associated with the delivery of therapeutics for pancreatic cancer treatment and discusses drug delivery strategies to minimize adverse effects associated with current chemotherapy options and to improve the efficiency of drug treatment.

Nanoparticles that Transcytosed through Cancer Cells Can Elicit Immune Response

Transcytosis is a crucial process that nanomedicines can experience in various delivery stages. However, little was known about whether it endows biofunctions to the nanomedicines. Here, we reported that transporting photodynamic nanoparticles across cancer cells via the endoplasmic reticulum (ER)-Golgi pathway formulated them with abundant neoantigens and damage-associated molecular patterns. The resultant nanoparticles (Tran-NPs) were potent in dendritic cell maturation and T cell activation. Meanwhile, the photodynamic Tran-NPs maintained their primary function of repolarizing immunosuppressive cells. The immune responses were observed in melanoma B16F10 tumor models. Our work suggested that the transcytosis process reprogrammed the nanoparticles with immunological properties, which might shed light on the design of nanomedicines.

Nanoparticles of VAV1 siRNA combined with LL37 peptide for the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer-related death, and it is highly resistant to therapy owing to its unique extracellular matrix. VAV1 protein, overexpressed in several cancer diseases including pancreatic cancer (PC), increases tumor proliferation and enhances metastases formation, which are associated with decreased survival. We hypothesized that an additive anti-tumor effect could be obtained by co-encapsulating in PLGA nanoparticles (NPs), the negatively charged siRNA against VAV1 (siVAV1) with the positively charged anti-tumor LL37 peptide, as a counter-ion. Several types of NPs were formulated and were characterized for their physicochemical properties, cellular internalization, and bioactivity in vitro. NPs' biodistribution, toxicity, and bioactivity were examined in a mice PDAC model. An optimal siVAV1 formulation (siVAV1-LL37 NPs) was characterized with desirable physicochemical properties in terms of nano-size, low polydispersity index (PDI), neutral surface charge, high siVAV1 encapsulation efficiency, spherical shape, and long-term shelf-life stability. Cell assays demonstrated rapid engulfment by PC cells, a specific and significant dose-dependent proliferation inhibition, as well as knockdown of VAV1 mRNA levels and migration inhibition in VAV1⁺ cells. Treatment with siVAV1-LL37 NPs in the mice PDAC model revealed marked accumulation of NPs in the liver and in the tumor, resulting in an increased survival rate following suppression of tumor growth and metastases, mediated via the knockdown of both VAV1 mRNA and protein levels. This proof-of-concept study validates our hypothesis of an additive effect in the treatment of PC facilitated by co-encapsulating siVAV1 in NPs with LL37 serving a dual role as a counter ion as well as an anti-tumor agent.

Unraveling the Plasma Protein Corona by Ultrasonic Cavitation Augments Active-Transporting of Liposome in Solid Tumor

Ligand/receptor-mediated targeted drug delivery has been widely recognized as a promising strategy for improving the clinical efficacy of nanomedicines but is attenuated by the binding of plasma protein on the surface of nanoparticles to form a protein corona. Here, it is shown that ultrasonic cavitation can be used to unravel surface plasma coronas on liposomal nanoparticles through ultrasound (US)-induced liposomal reassembly. To demonstrate the feasibility and effectiveness of the method, transcytosis-targeting-peptide-decorated reconfigurable liposomes (LPGLs) loaded with gemcitabine (GEM) and perfluoropentane (PFP) are developed for cancer-targeted therapy. In the blood circulation, the targeting peptides are deactivated by the plasma corona and lose their targeting capability. Once they reach tumor blood vessels, US irradiation induces transformation of the LPGLs from nanodrops into microbubbles via liquid-gas phase transition and decorticate the surface corona by reassembly of the lipid membrane. The activated liposomes regain the capability to recognize the receptors on tumor neovascularization, initiate ligand/receptor-mediated transcytosis, achieve efficient tumor accumulation and penetration, and lead to potent antitumor activity in multiple tumor models of patient-derived tumor xenografts. This study presents an effective strategy to tackle the fluid biological barriers of the protein corona and develop transcytosis-targeting liposomes for active tumor transport and efficient cancer therapy.

Recent Advances in Well-Designed Therapeutic Nanosystems for the Pancreatic Ductal Adenocarcinoma Treatment Dilemma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with an extremely poor prognosis and low survival rate. Due to its inconspicuous symptoms, PDAC is difficult to diagnose early. Most patients are diagnosed in the middle and late stages, losing the opportunity for surgery. Chemotherapy is the main treatment in clinical practice and improves the survival of patients to some extent. However, the improved prognosis is associated with higher side effects, and the overall prognosis is far from satisfactory. In addition to resistance to chemotherapy, PDAC is significantly resistant to targeted therapy and immunotherapy. The failure of multiple treatment modalities indicates great dilemmas in treating PDAC, including high molecular heterogeneity, high drug resistance, an immunosuppressive microenvironment, and a dense matrix. Nanomedicine shows great potential to overcome the therapeutic barriers of PDAC. Through the careful design and rational modification of nanomaterials, multifunctional intelligent nanosystems can be obtained. These nanosystems can adapt to the environment's needs and compensate for conventional treatments' shortcomings. This review is focused on recent advances in the use of well-designed nanosystems in different therapeutic modalities to overcome the PDAC treatment dilemma, including a variety of novel therapeutic modalities. Finally, these nanosystems' bottlenecks in treating PDAC and the prospect of future clinical translation are briefly discussed.

Therapeutic Strategies to Overcome Fibrotic Barriers to Nanomedicine in the Pancreatic Tumor Microenvironment

Pancreatic cancer is notorious for its dismal prognosis. The enhanced permeability and retention (EPR) effect theory posits that nanomedicines (therapeutics in the size range of approximately 10-200 nm) selectively accumulate in tumors. Nanomedicine has thus been suggested to be the "magic bullet"-both effective and safe-to treat pancreatic cancer. However, the densely fibrotic tumor microenvironment of pancreatic cancer impedes nanomedicine delivery. The EPR effect is thus insufficient to achieve a significant therapeutic effect. Intratumoral fibrosis is chiefly driven by aberrantly activated fibroblasts and the extracellular matrix (ECM) components secreted. Fibroblast and ECM abnormalities offer various potential targets for therapeutic intervention. In this review, we detail the diverse strategies being tested to overcome the fibrotic barriers to nanomedicine in pancreatic cancer. Strategies that target the fibrotic tissue/process are discussed first, which are followed by strategies to optimize nanomedicine design. We provide an overview of how a deeper understanding, increasingly at single-cell resolution, of fibroblast biology is revealing the complex role of the fibrotic stroma in pancreatic cancer pathogenesis and consider the therapeutic implications. Finally, we discuss critical gaps in our understanding and how we might better formulate strategies to successfully overcome the fibrotic barriers in pancreatic cancer.

Tumor-Targeted Erythrocyte Membrane Nanoparticles for Theranostics of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) cells do not contain various receptors for targeted treatment, a reason behind the poor prognosis of this disease. In this study, biocompatible theranostic erythrocyte-derived nanoparticles (EDNs) were developed and evaluated for effective early diagnosis and treatment of TNBC. The anti-cancer drug, doxorubicin (DOX), was encapsulated into the EDNs and diagnostic quantum dots (QDs) were incorporated into the lipid bilayers of EDNs for tumor bio-imaging. Then, anti-epidermal growth factor receptor (EGFR) antibody molecules were conjugated to the surface of EDNs for TNBC targeting (iEDNs). According to the confocal microscopic analyses and biodistribution assay, iEDNs showed a higher accumulation in EGFR-positive MDA-MB-231 cancers in vitro as well as in vivo, compared to untargeted EDNs. iEDNs containing doxorubicin (iEDNs-DOX) showed a stronger inhibition of target tumor growth than untargeted ones. The resulting anti-EGFR iEDNs exhibited strong biocompatibility, prolonged blood circulation, and efficient targeting of TNBC in mice. Therefore, iEDNs may be used as potential TNBC-targeted co-delivery systems for therapeutics and diagnostics.

Nanoparticles and convergence of artificial intelligence for targeted drug delivery for cancer therapy: Current progress and challenges

Cancer is a life-threatening disease, resulting in nearly 10 million deaths worldwide. There are various causes of cancer, and the prognostic information varies in each patient because of unique molecular signatures in the human body. However, genetic heterogeneity occurs due to different cancer types and changes in the neoplasms, which complicates the diagnosis and treatment. Targeted drug delivery is considered a pivotal contributor to precision medicine for cancer treatments as this method helps deliver medication to patients by systematically increasing the drug concentration on the targeted body parts. In such cases, nanoparticle-mediated drug delivery and the integration of artificial intelligence (AI) can help bridge the gap and enhance localized drug delivery systems capable of biomarker sensing. Diagnostic assays using nanoparticles (NPs) enable biomarker identification by accumulating in the specific cancer sites and ensuring accurate drug delivery planning. Integrating NPs for cancer targeting and AI can help devise sophisticated systems that further classify cancer types and understand complex disease patterns. Advanced AI algorithms can also help in biomarker detection, predicting different NP interactions of the targeted drug, and evaluating drug efficacy. Considering the advantages of the convergence of NPs and AI for targeted drug delivery, there has been significantly limited research focusing on the specific research theme, with most of the research being proposed on AI and drug discovery. Thus, the study's primary objective is to highlight the recent advances in drug delivery using NPs, and their impact on personalized treatment plans for cancer patients. In addition, a focal point of the study is also to highlight how integrating AI, and NPs can help address some of the existing challenges in drug delivery by conducting a collective survey.

Novel Liposomal Formulation of Baicalein for the Treatment of Pancreatic Ductal Adenocarcinoma: Design, Characterization, and Evaluation

Pancreatic cancer (PC) is one of the deadliest cancers so there is an urgent need to develop new drugs and therapies to treat it. Liposome-based formulations of naturally-derived bioactive compounds are promising anticancer candidates due to their potential for passive accumulation in tumor tissues, protection against payload degradation, and prevention of non-specific toxicity. We chose the naturally-derived flavonoid baicalein (BAI) due to its promising effect against pancreatic ductal adenocarcinoma (PDAC) and encapsulated it into a liposomal bilayer using the passive loading method, with an almost 90% efficiency. We performed a morphological and stability analysis of the obtained BAI liposomal formulation and evaluated its activity on two-dimensional and three-dimensional pancreatic cell models. As the result, we obtained a stable BAI-encapsulated liposomal suspension with a size of 100.9 nm ± 2.7 and homogeneity PDI = 0.124 ± 0.02, suitable for intravenous administration. Furthermore, this formulation showed high cytotoxic activity towards AsPC-1 and BxPC-3 PDAC cell lines (IC₅₀ values ranging from 21 ± 3.6 µM to 27.6 ± 4.1 µM), with limited toxicity towards normal NHDF cells and a lack of hemolytic activity. Based on these results, this new BAI liposomal formulation is an excellent candidate for potential anti-PDAC therapy.

Extracellular matrix modulating enzyme functionalized biomimetic Au nanoplatform-mediated enhanced tumor penetration and synergistic antitumor therapy for pancreatic cancer

BACKGROUND

Excessive extracellular matrix (ECM) deposition in pancreatic ductal adenocarcinoma (PDAC) severely limits therapeutic drug penetration into tumors and is associated with poor prognosis. Collagen is the most abundant matrix protein in the tumor ECM, which is the main obstacle that severely hinders the diffusion of chemotherapeutic drugs or nanomedicines.

METHODS

We designed a collagenase-functionalized biomimetic drug-loaded Au nanoplatform that combined ECM degradation, active targeting, immune evasion, near-infrared (NIR) light-triggered drug release, and synergistic antitumor therapy and diagnosis into one nanoplatform. PDAC tumor cell membranes were extracted and coated onto doxorubicin (Dox)-loaded Au nanocages, and then collagenase was added to functionalize the cell membrane through lipid insertion. We evaluated the physicochemical properties, in vitro and in vivo targeting, penetration and therapeutic efficacy of the nanoplatform.

RESULTS

Upon intravenous injection, this nanoplatform efficiently targeted the tumor through the homologous targeting properties of the coated cell membrane. During penetration into the tumor tissue, the dense ECM in the PDAC tissues was gradually degraded by collagenase, leading to a looser ECM structure and deep penetration within the tumor parenchyma. Under NIR irradiation, both photothermal and photodynamic effects were produced and the encapsulated chemotherapeutic drugs were released effectively, exerting a strong synergistic antitumor effect. Moreover, this nanoplatform has X-ray attenuation properties that could serve to guide and monitor treatment by CT imaging.

CONCLUSION

This work presented a unique and facile yet effective strategy to modulate ECM components in PDAC, enhance tumor penetration and tumor-killing effects and provide therapeutic guidance and monitoring.

The tumor EPR effect for cancer drug delivery: Current status, limitations, and alternatives

Over the past three decades, the enhanced permeability and retention (EPR) effect has been considered the basis of tumor-targeted drug delivery. Various cancer nanomedicines, including macromolecular drugs, have been designed to utilize this mechanism for preferential extravasation and accumulation in solid tumors. However, such nanomedicines have not yet achieved convincing therapeutic benefits in clinics. Increasing evidence suggests that the EPR effect is over-represented in human tumors, especially in metastatic tumors. This review covers the evolution of the concept, the heterogeneity and limitation of the EPR effect in clinical realities, and prospects for alternative strategies independent of the EPR effect.

Nanoparticles targeting hematopoietic stem and progenitor cells: Multimodal carriers for the treatment of hematological diseases

Modern-day hematopoietic stem cell (HSC) therapies, such as gene therapy, modify autologous HSCs prior to re-infusion into myelo-conditioned patients and hold great promise for treatment of hematological disorders. While this approach has been successful in numerous clinical trials, it relies on transplantation of ex vivo modified patient HSCs, which presents several limitations. It is a costly and time-consuming procedure, which includes only few patients so far, and ex vivo culturing negatively impacts on the viability and stem cell-properties of HSCs. If viral vectors are used, this carries the additional risk of insertional mutagenesis. A therapy delivered to HSCs in vivo, with minimal disturbance of the HSC niche, could offer great opportunities for novel treatments that aim to reverse disease symptoms for hematopoietic disorders and could bring safe, effective and affordable genetic therapies to all parts of the world. However, substantial unmet needs exist with respect to the in vivo delivery of therapeutics to HSCs. In the last decade, in particular with the development of gene editing technologies such as CRISPR/Cas9, nanoparticles (NPs) have become an emerging platform to facilitate the manipulation of cells and organs. By employing surface modification strategies, different types of NPs can be designed to target specific tissues and cell types in vivo. HSCs are particularly difficult to target due to the lack of unique cell surface markers that can be utilized for cell-specific delivery of therapeutics, and their shielded localization in the bone marrow (BM). Recent advances in NP technology and genetic engineering have resulted in the development of advanced nanocarriers that can deliver therapeutics and imaging agents to hematopoietic stem- and progenitor cells (HSPCs) in the BM niche. In this review we provide a comprehensive overview of NP-based approaches targeting HSPCs to control and monitor HSPC activity in vitro and in vivo, and we discuss the potential of NPs for the treatment of malignant and non-malignant hematological disorders, with a specific focus on the delivery of gene editing tools.

Transformable nanoparticles to bypass biological barriers in cancer treatment

Nanomedicine based drug delivery platforms provide an interesting avenue to explore for the future of cancer treatment. Here we discuss the barriers for drug delivery in cancer therapeutics and how nanomaterials have been designed to bypass these blockades through stimuli responsive transformation in the most recent update. Nanomaterials that address the challenges of each step provide a promising solution for new cancer therapeutics.

Transcytosis-enabled active extravasation of tumor nanomedicine

Extravasation is the first step for nanomedicines in circulation to reach targeted solid tumors. Traditional nanomedicines have been designed to extravasate into tumor interstitium through the interendothelial gaps previously assumed rich in tumor blood vessels, i.e., the enhanced permeability and retention (EPR) effect. While the EPR effect has been validated in animal xenograft tumor models, accumulating evidence implies that the EPR effect is very limited and highly heterogeneous in human tumors, leading to highly unpredictable and inefficient extravasation and thus limited therapeutic efficacy of nanomedicines, including those approved in clinics. Enabling EPR-independent extravasation is the key to develop new generation of nanomedicine with enhanced efficacy. Transcytosis of tumor endothelial cells can confer nanomedicines to actively extravasate into solid tumors without relying on the EPR effect. Here, we review and prospectthe development of transcytosis-inducing nanomedicines, in hope of providing instructive insights for design of nanomedicines that can undergo selective transcellular transport across tumor endothelial cells, and thus inspiring the development of next-generation nanomedicines for clinical translation.

Advances in Antitumor Nano-Drug Delivery Systems of 10-Hydroxycamptothecin

10-Hydroxycamptothecin (HCPT) is a natural plant alkaloid from Camptotheca that shows potent antitumor activity by targeting intracellular topoisomerase I. However, factors such as instability of the lactone ring and insolubility in water have limited the clinical application of this drug. In recent years, unprecedented advances in biomedical nanotechnology have facilitated the development of nano drug delivery systems. It has been found that nanomedicine can significantly improve the stability and water solubility of HCPT. NanoMedicines with different diagnostic and therapeutic functions have been developed to significantly improve the anticancer effect of HCPT. In this paper, we collected reports on HCPT nanomedicines against tumors in the past decade. Based on current research advances, we dissected the current status and limitations of HCPT nanomedicines development and looked forward to future research directions.

Navigations of the targeting pathway of nanomedicines towards tumor

INTRODUCTION

Nanomedicines (NMs) have emerged as a promising approach for revolutionizing cancer treatment outcomes, mainly due to their benefits in the tumor targeted delivery of therapeutics. The preferential accumulation of NMs in tumor has been widely verified by macroscopical technologies. Accordingly, several classic and emerging targeting mechanisms have been proposed to support the tumor-specific delivery of NMs. The targeting mechanism has been a topic of intensive interest and controversy in the field of NMs development. Especially, the mechanisms by which NMs target tumor remain elusive.

AREA COVERED

This topical review mainly discussed the evolution of the targeting mechanisms, crucial issues associated with each mechanism, and confused debates among the mechanisms. The targeting mechanisms of tumor-specific NMs discussed here include the enhanced permeability and retention (EPR) effect, protein corona-mediated targeting delivery, circulating cell mediated transportation, and transcytosis.

EXPERT OPINION

It is of great significance for ultimate clinical translation to have more comprehensive considerations on the mechanism driving the pathway of NMs toward tumors. Our thoughts in this review are expected to provide comprehensive understanding on the mechanisms and elicit thorough explorations on new mechanism to renovate the knowledge framework of NMs delivery.

Deep-Penetrating Triple-Responsive Prodrug Nanosensitizer Actuates Efficient Chemoradiotherapy in Pancreatic Ductal Adenocarcinoma Models

Chemoradiotherapy (CRT) is the most accepted treatment for locally advanced pancreatic ductal adenocarcinoma (PDAC) and can significantly improve the R0 resection rate. However, there are few long-term survivors after CRT. Although some polymer nanoparticles have shown potential in alleviating the dose-limiting toxicity and assisting the chemotherapy of PDAC, there are few efficient nanosensitizers (NS) available for CRT of this malignancy, especially in the context of its hypoxic nature. Herein, based on the biological features of PDAC, a γ-glutamyl transpeptidase (GGT)/glutathione (GSH)/hypoxia triple-responsive prodrug NS to overcome the biological barrier and microenvironmental limitations confronted by CRT in PDAC is developed. Due to triple-responsiveness, deep tumor penetration, GSH/hypoxia-responsive drug release/activation, and hypoxia-induced chemoradio-sensitization can be simultaneously achieved with this NS. As a result, tumor shrinkage after CRT with this NS can be observed in both subcutaneous and orthotopic PDAC models, foreshadowing its potential in clinical neoadjuvant CRT.

Inducible endothelial leakiness in nanotherapeutic applications

All intravenous delivered nanomedicine needs to escape from the blood vessel to exert their therapeutic efficacy at their designated site of action. Failure to do so increases the possibility of detrimental side effects and negates their therapeutic intent. Many powerful anticancer nanomedicine strategies rely solely on the tumor derived enhanced permeability and retention (EPR) effect for the only mode of escaping from the tumor vasculature. However, not all tumors have the EPR effect nor can the EPR effect be induced or controlled for its location and timeliness. In recent years, there have been exciting developments along the lines of inducing endothelial leakiness at the tumor to decrease the dependence of EPR. Physical disruption of the endothelial-endothelial cell junctions with coordinated biological intrinsic pathways have been proposed that includes various modalities like ultrasound, radiotherapy, heat and even nanoparticles, appear to show good progress towards the goal of inducing endothelial leakiness. This review explains the intricate and complex biological background behind the endothelial cells with linkages on how updated reported nanomedicine strategies managed to induce endothelial leakiness. This review will also end off with fresh insights on where the future of inducible endothelial leakiness holds.

Strategies to enhance drug delivery to solid tumors by harnessing the EPR effects and alternative targeting mechanisms

The Enhanced Permeability and Retention (EPR) effect has been recognized as the central paradigm in tumor-targeted delivery in the last decades. In the wake of this concept, nanotechnologies have reached phenomenal levels in research. However, clinical tumors display a poor manifestation of EPR effect. Factors including tumor heterogeneity, complicating tumor microenvironment, and discrepancies between laboratory models and human tumors largely contribute to poor efficiency in tumor-targeted delivery and therapeutic failure in clinical translation. In this article, approaches for evaluation of EPR effect in human tumor were overviewed as guidance to employ EPR effect for cancer treatment. Strategies to augment EPR-mediated tumoral delivery are discussed in different dimensions including enhancement of vascular permeability, depletion of tumor extracellular matrix and optimization of nanoparticle design. Besides, the recent development in alternative tumor-targeted delivery mechanisms are highlighted including transendothelial pathway, endogenous cell carriers and non-immunogenic bacteria-mediated delivery. In addition, the emerging preclinical models better reflect human tumors are introduced. Finally, more rational applications of EPR effect in other disease and field are proposed. This article elaborates on fundamental reasons for the gaps between theoretical expectation and clinical outcomes, attempting to provide some perspective directions for future development of cancer nanomedicines in this still evolving landscape.

EGF Receptor-Targeting Cancer Therapy Using CD47-Engineered Cell-Derived Nanoplatforms

Introduction

Avoiding phagocytic cells and reducing off-target toxicity are the primary hurdles in the clinical application of nanoparticles containing therapeutics. For overcoming these errors, in this study, nanoparticles expressing CD47 proteins inhibiting the phagocytic attack of immune cells were prepared and then evaluated as an anti-cancer drug delivery vehicle.

Methods

The CD47+ cell-derived nanoparticles (CDNs) were prepared from the plasma membranes of human embryonic kidney cells transfected with a plasmid encoding CD47. And the doxorubicin (DOX) was loaded into the CDNs, and anti-EGF receptor (EGFR) antibodies were conjugated to the surface of the CDNs to target tumors overexpressing EGFR.

Results

The CD47+iCDNs-DOX was successfully synthesized having a stable structure. The CD47+CDNs were taken up less by RAW264.7 macrophages compared to control CDNs. Anti-EGFR CD47+CDNs (iCDNs) selectively recognized EGFR-positive MDA-MB-231 cells in vitro and accumulated more effectively in the target tumor xenografts in mice. Moreover, iCDNs encapsulating doxorubicin (iCDNs-DOX) exhibited the highest suppression of tumor growth in mice, presumably due to the enhanced DOX delivery to tumor tissues, compared to non-targeting CDNs or CD47- iCDNs.

Discussion

These results suggest that the clinical application of biocompatible cell membrane-derived nanocarriers could be facilitated by functionalization with macrophage-avoiding CD47 and tumor-targeting antibodies.